As woseshaman explained, The medallions you use, the ones you get upon giving sacrifices, they don't have any effect on whether you'll receive the blessing or not, your hits during the fight do.
The only reason they let you sacrifice is to:
1- Increase your reputation so you can get better badges to get better blessings during fights and get more Reputation Rating.
2-So you can use the medallion and during that 2 hours' time you can receive the blessing that's 1 step upper than your badge.
For example:
This is grey badge blessing and
this is the blessing you get when you have grey badge + use medal.
However, some random mentor will come and start talking trash like:
lmeoh kharkoal, yur stuped, plis log off te internet en lern its nöt teh medulleon, sömtimez ü dön't get effekt fröm mödüllon.
But yeah, that's pretty much like how i said.